User interface for a portion of a display screen



FIG. 1 is a front view of a user interface for a portion of a display screen showing our new design; and,

FIG. 2 is a front view thereof, on an enlarged scale, the claimed portion is shown separately for clarity of illustration.

The broken line showing of various regions and the unshaded areas there within form no part of the claimed design. The broken line showing of the display screen is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a user interface for a portion of a display screen, as shown and described. 